Power supply control for low voltage circuits using high threshold switch transistors

A power system for controlling power to low voltage CMOS circuits. The power system can be used in circuits having a low voltage supply and a high voltage supply, wherein the low voltage supply powers low voltage circuit components and the high voltage supply powers high voltage circuit components. The power system comprises a first switch coupled between the low voltage supply and the low voltage circuit components, a second switch coupled between the low voltage circuit components and a circuit ground, and a power control circuit coupled to the high voltage supply and the circuit ground and having a control output coupled to the first and second switches, wherein when the control output is in a first state the low voltage supply and the circuit ground are connected to the low voltage circuit components and when the control output is in a second state the low voltage supply and the circuit ground are disconnected from the low voltage circuit components.